(A) General. Every habitable space shall have at least one openable window. The total openable area of the window in every room shall be equal to at least 45% of the minimum glazed area required in § 151.365.
(B) Exception. Where rooms and spaces without openings to the outdoors are ventilated through an adjoining room, the unobstructed opening to the adjoining room shall be at least 8% of the floor area of the interior room or space, but not less than 25 square feet (2.33 m2). The ventilation openings to the outdoors shall be based on a total floor area being ventilated.
(2009 Code, § 29-4-9)